Telephone-exchange central-station switchboard apparatus.



No. 666,444. Patented 1an. *22, 190|.

6.. K. THoMFsoN 6 E. c. 6665s. TELEPHONE EXCHANGE CENTRAL STATION SWITCHBAHD APPARATUS.

(Application led Feb. 13. 1900.)

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Patentedlan. 22, mol.

TELEPHONE EXCHANGE CENTRAL STATION SWITCHBABD APPARATUS.

(Application filed Feb. 13. 1900.)

(No Model.)

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2 Sheets-Sheet 2.

Marten Sintes PATENT Ottimi GEORGE KNOX THOMPSON, OF MALDEN, AND ERNEST CLIFTON ROBES, OE

MEDFORD, MASSACHUSETTS, ASSIGNORS TO THE AMERICAN BELL TELE- PHONE COMPANY, OE BOSTON, MASSACHUSETTS.

TELEPHONE-EXCHANGE CENTRAL-STATION SWITCHBOARD APPARATUS.

SPECIFICATION forming part of Letters Patent No. 666,444, dated January 22, 1901.

Application led February 13, 1900. Serial No. 5,081. (No model.)

To all whom t may concern,.-

Be it known that we, GEORGE KNOX THOMPSON, residing at Malden, and ERNEST CLIFTON ROBES, residing at Medford, in the county of Middlesex and State of Massachusetts, have invented certain Improvements in Telephone-Exchange Central-Station Switchboard Apparatus, of which the following is a specification.

This invention relates to telephone-exchange central-station switchboard apparatus, and particularly concerns appliances for conveying between different switchboards instructions regarding the interconnection of substation-lines or the'connection of substation-lines with the lines leading to other central stations belonging to either the same exchange or to other exchanges.

In telephone-exchange trafiic messages of a certain class are known as toll messages. In general these are messages between substations of diierent exchanges or between widely-separated exchange districts, and the lines over which they pass between exchanges are called toll-lines. They require special attention and care on the part of the operating force ot' the central station or the several central stations concerned, and for these messages a special charge is made. Our invention is especially well adapted for use in association with these toll-lines. These conditions render it necessary that the names and telephone-numbers of the call-originating and called-for substations, together with information as to the date, the time of day, and the time consumed in the exchange of conversation Or the transmission of the message, shall be entered on a blank form termed the ticket This is done, first, to avoid the confusion and liability to error, which, as experience shows, is apt to occur if the aboverecited information be transmitted orally between the several operators, and, second, to furnish a record of the transaction for future reference.

In the toll business as at present conducted a substation desiring a toll connection on first sending the call in the usual way is responded lo by a receiving-operator stationed at the switchboard or switchboard-section Where the call-receiving devices of the line of such substation are placed, to Whom the orderfor the desired connection is given. The Order, with the necessary detailed information, is at Once entered upon the ticket and the connection is to be made or completed by a toll-line operator at another switchboard or switchboard-section, termed the toll-switchboard. These toll-boards may be arranged singly or in pairs at diierent portions of the entire switchboard or switch apparatus, and it is therefore requisite that the ticket stating the order shall be transferred from the operator who records the order to the particular operator or group of Operators who handle the toll-lines extending to the distant point with which communication is to be established. It is furthermore desirable that after conversations are completed and their duration properly recorded on the tickets or slips the said tickets shall be forwarded to some central pointa clearing-house, so to speak-whence they may be collected when a sufficient number shall have accumulated or at the close of the day. Heretofore it has been customary to distribute and collect the tickets by messengers.

The object of our invention is to dispense with messengers and to provide a system and a convenient and serviceable apparatus for the noiseless, accurate, and swift conveyance of the tickets, first, from the switchboard or section where the orders are received and written to the various toll switchboards or sections where the desired connections are to be made or completed, and, second, to forward the said tickets after the business to which they refer has been transacted to some suitable depository for ultimate collection. To this end we have invented a system of pneumatic-tube transmission extending between switchboards and from the switchboard iinally concerned in the establishment ot' complete intercommunication and a 'orm of transmission-tube for use therein which is capable of conveying between its terminals the tickets, the paper information slips or cards which are required to be transferred from one switchboard or switchboardsection to another loosely and without the IOO carrier or receptacle, which, so far as we know, has uniformly been a concomitant of pneumatic-tube transmission. We have de* vised a form of tube capable of eiiciently performing this work, the same having a rectangular bore and being preferably thin or dat, as will be more particularly shown and described herein. We have also found that by bending or folding one end of these tickets to an angle with their main portion they become qualified to act as a piston within a traiismission-tube of such form or character, and under the impulsion of a current of air traversing the lube, preferably caused by the establishment ot' a vacuum at the receiving end thereof acting upon them in their capacity as a piston, they are rapidly drawn through the said tube from the end at which they are inserted to the receiving end where they are delivered.

Our invention provides that a pneumatic tube or a plurality of tubes shall especially be extended between the switchboardswhere substatiowcalls are originally received to the toll-line switchboards, which are intermingled with and variously placed among the others, the card-receiving end of the said tube or tubes being at the regular board and the delivery end of the tube at the toll-board. It also provides that from the toll-switchboard a supplementary pneumatic tube of the saine general character shall extend to a suitable central depository and that if there be a plurality of toll-boards each shall have a branch tube leading into andr coalescing with the main supplementary tube extending to such depository. Our invention likewise consists in the combination, with the said pneumatic transmission and supplementary tubes, of an exhaust or extension tube placed at the receiving end and leading from an airpump or such equivalent device as may be employed to establish the requisite current of air in the proper direction through the said pneumatic tubes, and appropriate and convenient devices also at the receiving end to effectuate and control the proper retention and delivery of the arriving tickets. rlfhe said devices comprise a valve placed at the junction of the main and exhaust tubes and so arranged that while normally it holds the air-passage between the tubes open and the delivery-passage of the ticket closed it can be so altered as to close the air-passage and open the ticket-delivery passage, means for operating the valve when desired, means for bringing the arriving ticket torest and for holding it Within the tube until the aircurrent bythe action of the valve shall have been cut off and for then freeing the same, and mechanism connecting the valve-actuating means with the ticket-holding devices for the release operation of the latter, the same being organized to liberate the ticket and permit its delivery as soon as the air-passage shall have been closed.

In the drawings accompanying this specication, Figure 1 is an elevation, partly in section, showing a pneumatic-tube system between the positions on a centra1station switchboard apparatus of a receiving-operator and a connecting or toll operator, the receiving or delivery end of the tube being at the latter position. Fig. 2 is a plan view of the supplementary or return system, showing a tube extending from a number of connecting-operators switchboartl-sections with which the said tube is connected by branches to a common receptacle or depository. Fig. 3 is a side view, on a larger scale, ot' the re cei'ving end of the transmissiomtube and ter minal devices. Fig. 4 is a similarly-enlarged side view of the receiving end of the tube, partly in longitudinal section, to show the valve between the transmission and exhaust tubes, the same being open to the exhaust; and Fig. 4 indicates a section of the receiving-end terminal devices with the passage between the tubes closed by the said valve. Fig. 5 is an end view of the valve-cylinder looking in thedirection indicated by the arrow, Fig. 3. Figs. 6 and 7 are cr`oss-sections of the-transmissionftube on lines y y of Fig. 4 and c of Fig. 3, respectively, the latter indicating the air-channels at the sides ofthe transmission-tube leading to the exhaust. Fig. 8 is a perspectiveview of the tube-inclosed portion of the elbow-lever, serving as aretarding device. Fig. 9 is a perspective View of a satisfactory form of ticket or slip, and Fig. lO is a diagram indicating the associated switchboard and pneumatic-tube arrangement.

A represents a switchboard or switch boardsection where the calls of a number of substation telephone-lines are answered or initially attended to, and B is a switchboard or section where connections of the substationlines of any switchboard-section of the former class are made with trunk or toll lines leading to other central stations. As indicated in Fig. 10, a, a2, and a3 represent substation-lines connectedprilnarily with the substation-board and adapted to have their calls answered thereat. The toll-board comprises switch-terminals of toll or other central-station lines z z2, and the said lines at both boards are provided with suitable switchsockets J J2 and with switch-plug and cord connection devices, as usual, these being indicated at board A by the letter K and at board B by 7c.

For the necessary establish ment of communication between substation-boards and tollboards the substation-lines a a? c3, assigned to any switchboard A, may be continued to the boards B of the latter class, as shown by extension a4 of line a3, which has a switchsocket at board B on the well-known multiple switchboard principle, or, dispensing with such an arrangement, office-trunks extending between switch-sockets of the switchboards concerned may be employed, such a trunk being indicated at w as uniting the IOO IIO

boards A and B. It should, however, also be understood that in paractice the switchboardsections are generally placed end to end in close juxtaposition, 'so as to make a long continuous structure, and that the toll-line boards or sections are often arranged in pairs and may be intermingled among the su ostation boards or sections or otherwise placed at different portions of the entire switchboard apparatus.

M is a pneumatic tube extending between the switchboards, having an open terminal 'O at the substation-switchboard and suitable terminal devices o at the toll-board, holding a channel open to an extension or exhaust tube N, connecting with an air-pump P, and at the same time maintaining closed the passage through which the arriving tickets are delivered". The air-pump is arranged to produce and maintain a partial vacuum at the receiving end of the transmission-tube M, thus establishing through the said tube a current oi' air from the transmitting end at A to the receiving end at B. Any required number ot" such transmission-tubes and exhaust-lube extensions may be arranged and employed, as indicated by the incomplete extension-tubes n, attached to the main exhausttnbe N2, which connects directly to the air pump P.

ln our system of pneumatic transmission we dispense with the use of carriers,and cards, tickets, or paper slips are transmitted loosely through the tubes. This is accomplished by making the tubes rectangular in cross-section and flat, as shown in Fig. 6, by employing tickets T having a width slightly smaller than but corresponding to the length of the crosssection of the bore of the tube, and by bending up or folding the end tof the said tickets, shown in Fig. 9, in such manner and to such a degree that the said folded-up portion substantially closes the bore of the tube and becomes practically a piston therefor, as well as the card or ticket whereon a message to be transmitted is inscribed.

In Fig. 2 is indicated the supplementary system whereby the tickets T, which have reached the toll-boards B through the transmission-tubes M and have had their calls completed, can be sent to suitable depository C, from which they may be regularly collected. M2 is the common main tubo of this supplementary system, and m2 branch tubes therefor extending each from one or more toll-boards and all leading to and merging in the common main tube, which at the depository C connects with the extension-tube N?, leading from the air-pump and has ticket-delivery terminal appliances similar to those of the transmissiontubes M at switchboards B, which are presently to be described. Both tubes are open at the transmitting end and present merely a rect-angular slot-shaped aperture,\\ herein the ticket to be transmitted is inserted. O represents this aperture for the transmission-tube at board A, and O2 a similar aperture in the supplementary tube at board B; but at the receiving or delivery ends ot" these tubes it is necessary to provide suitable means for noting the arrival of a ticket, for holding it in place on arrival, so that it cannot be drawn into the exhaust, for cutting ott the exhaust during delivery, and for enabling its egress from the tube to be conveniently and ex penditiously accomplished. For these purposes the tubes are each fitted with a valve-casing chietiy consisting of a short horizontal cylinder V, the axis ot' which is perpendicular to the center line of the main tube, but in part ot' a chamber V2, overlapping the end of the rectangular main tube, which in its inclosed portion is provided with air passages or channels g g2, through which, as indicated in Fig. 7 by the arrows, the air passes, when the channel to the air-pump is open, into the chamber V2 and thence to the exhaust N.

Within the valve-cylinder, which may be entirely open at the rear side, is a valve c, mounted on an axis o4 and having a wing or gate c2 and an actuating-lever Q, which can be moved between limits s and s2 for the purpose of bringing the valve to eitherV of the two positions necessary to the operation of the system. The normal position of the valve is indicated in Fig. 4, where the lever Q being at its lowest point s the valve-gate c2 closes the ticket-egress passage, while the front end of the valvechamber V2 is unclosed, affording free passage of air between the said chamber and the exhaust-pipe N,leading tothe airpump. The ticket-delivery position of the valve is shown by Fig. 4C. Here the lever has been moved to its upper limit s2 and the gate u2 has been transferred from its position closing the ticket-passage to one where, leaving this passage open, the air-passage to the exhaust is closed by the presence of the said gate across the opening of the air-chamber V2.

Mounted in close association with the valve devices is a bell-crank or elbow lever E, pivoted at y. The longer arm e of this lever lies within the tube M and is very nearly as wide as the rectangular cross-section of the tube M is long. As separately shown, this arm is subdivided into several branches or fingers, which, acting in a claw-like manner on the ticket rapidly approaching the end of the tube, retards its motion and, in conjunction with the stop device furnished by the valvegate u2, brings it to rest and holds it within the tube,ready for delivery as soon as the passage for its egress is opened. The shorter leveiearm e2 is outside of the tube, and thelever normally is held in place, so that the fingers of its longer arm will be made to press against the lower inner surface of the tube by the spring H.

The portion of the rectangular tube M which is immediately in rear of the valve-cylinder and which contains the lever-arm e is provided in its upper wall with a window h, of glass or like transparent material, through IOO IIO

which an arriving ticket which has been brought to rest beneath the fingers of said arm e may be seen.

The web r3 of the valve 11 has a flat rear surface, which is adapted when the said valve is moved to the position where the ticketegress is opened to form a continuation of the inclined floor of the tube and to facilitate the delivery of the ticket by serving as a mechanical bridge, whereby the said ticket is enabled to cross the valve-cylinder cavity into which otherwise it might be drawn.

Secured to one end of the valve-axis 'U4 is a crank c, and a link CZ, slotted atj, engages at one end with the pin c2 of said crank and by its slot with a similar pin e3, carried by the end e2 of the short arm of the elbow-lever E. By means of this mechanism the longer arm of the lever is lifted and caused to release the ticket whenever the valve-actuating lever Q is operated to move the valve from its resting position to that wherein it opens the discharge position of the ticket and closes the passage between the transmission and exhaust tubes and in consequence of such operation. Itis, however, desirable that the operation of the valve shall be slightly in advance of the release of the tickct, so as to avoid the release of the ticket before the valve-web is broughtinto line with the tube,and this is provided for by the slotj of the link cl, which permits the said link to move a considerable distan ce before pressure is exercised on the leverarm e2. Itis also desirable that the valve and elbow-lever shall be restored to their normal positions after the discharge of a ticketwithout the necessity of special action of the operator to that end, and means are provided forcarrying this out. The spring H, attach ed to the pin e3 of the elbow-lever arm e2, is adapted to perform this service for the said elbow-lever, and the spring H2, shown as being attached to the crank c on the valve-axis at one end and to any suitable fixed point q at the other, is adapted to restore the valve.

The operation of these devices may briefly be adverted to. When a call from one of the substation-lines of switchboard A has been received for a substation of an outlying eX- change to be reached b v one of the toll-lines of switchboard B, the ticket for this interconnection is made out, as hereinbefore described, and affords all necessary information. The said ticket is then deposited by the original receiving-operator in the aperture O of the transmission-tube, its end being first turned up, as shown. It is drawn rapidly through the tube by the air-current produced by the air-pu mp, or, in other words, by the partial vacuum or rarefaction at the receiving end, and, reaching switchboard B, passes under the iingers of the elbow-lever and is at once observed through the window or may be made to announce itself by a signal in any well-known manner. The toll operator operates the lever Q, and thereby cuts ol the air-pump or exhaust connection and opens the delivery-gate. The ticket being then released slides through the valve-cylinder over the inclined surface provided for it, its motion being accelerated by the momentum of the column of air within the tube and behind it. The toll operator makes the requisite circuit connections and when the call is completed deposits the ticket in the aperture O2 of the supplementary tube, through which it is carried to the clearing-house, depository, or any suitable point for accumulation and collection.

The terminal devices may obviouslybe considerably modified without departing from our in vention. For example, the air-chamber V2, with which the side air-passages g g2 from the main tube connect,'may be extended farther along the said tube, as indicated in dotted lines in Fig. 4, and the side air-[mssages themselves may then be placed, as in like manner indicated, farther back in the main tube. Such a modification is sometimes an advantage, as there is then a space at the end of the tube where the air is quiet and the ticket while kept therein will not Hutter against the arms of the lever e.

Having thus fully described our invention, we define it in the following claims:

l. In a pneumatic system, the combination with a transmission-tube, of a card or ticket having a part approximately the shape of the bore of the tube and adapt-ed to act as a piston therefor, whereby the said ticket may be propelled through the said tube.

2. In a pneu matic-tube apparatus, the combination substantially as described herein, of

a transmission-tu be having a fiat rectangular bore; with cards or tickets having flanged or turned-up ends adapted to loosely fit the bore of said tube and to serve as a piston therefor; whereby the tickets may be propelled through the said tube, dispensing with the aid of carriers.

3. The combination substantially as hereinbefore set forth, of a iiat rectangular transmission-tube; means for establishing a constant current of air through said tube; and cards or tickets of a width corresponding to the length of the internal cross-section of said tu be and having flanged or bent ends correspending in width to the width of the bore of said tube; whereby each card is enabled to practically close the tube when inserted therein, and to be propelled or drawn therethrough by the said air-current.

4c. The combination in a telephone central- IOO station switchboard apparatus, of a series of substation-line switchboard-sections; and a series of toll-line switchboard-sections; with a pneumatic-tube instruction-ticket system, comprising a group of pneumatic tubes extending between switchboards of one series and those of the other, and adapted for the conveyance ot loose instruction-tickets uniformly from the switchboard-sections of the substation-line series to those of the toll-line series; and a supplementary pneumatic System consisting of branch transmission-tubes leading from the switchboard-sections of the Jroll-line series respectively, and a common receiving-tube in which the said branches merge, leading to a suitable depository; substantially as set forth.

5. The combination with a pneumatic tube of rectangular cross-section adapted for the transmission of tickets, paper slips, &c.,with out a carrier; and an exhaust-tube at the receiving end thereof leading to a vacuum or air-current producing apparatus; of a leveractuated valve capable of being placed in either of two positions, and controlling the connection between the said main and exhaust tubes, and the direct or ticket delivery opening or egress of the former, the normal position of said valve being such as tol establish the air-passage between the transmissiontube and eXhaust-tube,and to close the ticketegress of the former, and the position wherein it is placed on the arrival of a ticket being such as to close the said air-passage or cut olf the vacuum-producing apparatus, and to open the ticket-egress of the transmissiontube and thus permit the delivery of the ticket; substantially as set forth.

6. ln combination 'with a pneumatic-transmission tube adapted for the conveyance loosely within the said tube of tickets, paper slips, dac., by means of a current of air; and an extension or exhaust tube therefor at the receiving end thereof, leading to an air-pump for the production of such air-current; a Valve placed at the junction of said transmission and exhaust tubes and adapted to open the air-passage between them, and to close the ticket-delivery passage of the former, or conversely to close the said air-passage and open the said ticket-passage; means for manually actuating the said valve; a spring-arm within the transmission-tube adapted to act as a retarding device for the ticket, and to stop the same on its arrival, until the valve is opened to permit the delivery thereof; and link-andlever mechanism uniting the actuating devices of the said valve to the said spring device in such manner as to free the ticket from the said device, as soon as the said valve is operated to close the air-passage; substantially as, and for the purposes set forth.

7. The combination of a pneumatic transmission-tube for the conveyance loosely within the said tube of tickets or slips of paper by means of a current of air traversing the tube from the transmitting to the receiving end thereof; an exhaust-tube leading from the said receiving end of the transmittingtube to the air-pump producing such air-current; with a valve controlling the air-passage between the said transmission and exhaust tubes, and adapted to close and open the same as required; a stop mechanically attached to, or forming part of said valve, normally opposing the egress of the arriving tickets; a window of glass or like transparent material in the transmitting-tube, immediately in rear of the said stop; and means as indicated for operating the said valve to close the air-passage, and for simultaneously removing the said stop to permit the delivery of a ticket, when the sameis observed through the Window to have arrived; substantially as specified.

8. In combination with a pneumatic transmission-tubeA M; and an extension-tube N therefor connecting with an airpump or equivalent means for establishing a current of air through the transmission-tube from its transmitting to its receiving end; of the valvecasing V placed at the junction of the said tubes; the valve Q2 hung in pivots or bearings within the said casing, andcontrolling the air-channel between the said tubes, and also the ticket-outlet of the transmissiontube; the actuating-lever Q for the said valve, attached thereto, and movable between two positions, in the said valve-casing; the spring-controlled pivoted elbow-lever E having one arm e within and the other e2 outside of the transmission-tube; the crank c secured to the valve-axis; and the slotted link d having its ends attached respectively to the said crank c, and the arm e2 of lthe elbow-lever; substantially as and for the purposes specified.

In testimony whereof we have signed our names to this specification, in the presence of two subscribing witnesses, this 6th day of February, 1900.

GEORGE KNOX THOMPSON. ERNEST CLIFTON ROBES.

Witnesses:

GEo.W1LLIs PIERCE, JOSEPH A. GATELY. 

